Many people of a certain age remember Mazda's catchy ads from the 1970s. "Piston engines go boing-boing," they said. "Mazda goes hummm." The voiceover sang: "There's nothing like it on the road today; the rotary engine is here to stay."
The last Mazda using the rotary, which won fans with its ability to generate more power than traditional power plants of the same size, has rolled off the assembly line at the company's Hiroshima factory and headquarters.
The 45-year rise and fall of the engine tells a broader story of the past, present and — Mazda is betting — future of automaking. Shoji Meguro's very mixed feelings give a window into the reasons.
"Fuel efficiency is horrible," said Meguro, 41, a music producer who drives a Mazda RX-8 sports coupe. "But I don't know any car that beats this. I'm going to miss it."
The only unprofitable Japanese automaker said it believes demand for more environmentally friendly cars will continue to grow and help it post its first profit in five years.
"Production of the RX-8 will end, but the rotary engine will live on as an important part of Mazda's spirit," Mazda President Takashi Yamanouchi told Bloomberg.
Originally developed by engineer Felix Wankel in Germany after World War II — it was also called the Wankel engine - the technology was licensed by Mazda in 1961 from Audi NSU Auto Union, now a unit of Volkswagen.
Consisting of a three-cornered rotor in an oval chamber, the engine is typically lighter than piston power plants, with fewer moving parts. That enables additional power and acceleration without the bulk of traditional engines.
The rotary engine in the current model RX-8 reaches 8200 revolutions per minute before hitting the maximum level at which it's designed to operate without causing damage. That compares with 7000 rpm for Toyota's 86 sports car.
It's that sort of performance than won over Kenichi Tsunoda, who joined a Mazda dealership in 1992 as a mechanic after graduating from school and bought an RX-7 two-door sports coupe with the rotary shortly after.
Tsunoda's dream was to "touch and play with rotary engines every day," he said at the Mazda showroom he now manages in Chiba, adjacent to Tokyo.
After the debut of the Cosmo Sport in 1967, Mazda made almost two million vehicles with variations on the Wankel engine. The company's rotary-powered 787B became the first Japanese-made car to win the Le Mans endurance race in 1991.
"The engine's roar and its beautiful appearance were loved by those who saw the Mazda 787B win the Le Mans race," said Yamanouchi, who joined the company in 1967, the same year the rotary entered production.
While the rotary was lighter than many piston power plants, they weren't more efficient because they typically used oil injection to lubricate seals and a greater proportion of fuel went unburned. That led both to bad gas mileage and higher emissions than many other cars.
Annual production peaked at 239,871 in 1973, the year of the Arab oil embargo.
Tighter emission standards and higher gas prices combined to hasten its demise. While Mazda added the engine to both sedans and sports cars in the 1970s and introduced a turbo-charged version of the Cosmo RE in 1982, the rotary lost favour, and by 2003, only the RX-8 still had it.
With the rotary-powered RX-8 guzzling twice as much gasoline as Toyota's Corolla, the biggest-selling gasoline car in the world, and about 40 per cent more than Toyota's 86 sports car, Mazda faced a struggle to find buyers if it persisted with the technology.
In addition, the RX-8 rotary failed diagnostics tests for the Euro 5 emission requirements that came into effect in 2010, said Michiko Terashima, a spokeswoman for Mazda. The rules govern what cars can be sold in Europe.
By 2010, the company was making just 2896 RX-8s.
"Fuel emission standards can mean the life or death to some products," said Masato Sase, a Tokyo-based consultant at Deloitte Tohmatsu Consulting Co. "Still, those standards sometimes lead companies to improve, and can serve as drivers of new technology."
Mazda is turning to what it calls SkyActiv, which is a suite of technologies based on diesel and gasoline engines and includes new automatic transmissions and lighter car frames to cut down on fuel use.
The technology may be enough to keep Mazda competitive for the next decade, Kurt Sanger, a Tokyo-based auto analyst at Deutsche Bank AG, wrote in a report last year.
Mazda fell 1.9 per cent to 102 yen at the close of trading in Tokyo. The carmaker's shares have declined 25 per cent this year after dropping the most among Japan's five largest automakers last year.
Mazda's reliance on export sales exacerbates its vulnerability to gains in the value of the yen. The company produces almost 70 per cent of its cars in Japan, of which 80 per cent are shipped overseas, the highest ratio in the industry.
The company, which leases about eight hydrogen-powered cars to organisations including the Hiroshima and Yamaguchi prefectural governments in western Japan, has said it will continue research on rotary engines to test more environmentally friendly technology.
Separately, Mazda is also planning to introduce an electric car next year using hydrogen to fuel the rotary engine and generate power for the car's battery.
The new CX-5, the first sports utility vehicle fully incorporating SkyActiv, will exceed the initial sales plan of 160,000 units while the Mazda6, or Atenza, will become the second model to fully integrate the technology and enter the market this year, according to Yamanouchi.
After introducing the CX-5 SUV in Japan this February, Mazda said it received 8000 orders for the car in one month, as President Yamanouchi expects annual global sales of the model to come close to 200,000.
Mazda plans to have eight models that fully adopt Skyactiv and increase the proportion of its sales using the technology to 80 per cent by March 2016.
News of the rotary's demise prompted Mazda to add 1000 cars to its final production run as devotees sought to secure an RX-8.
"One of the buyers who rushed in was a gentleman in his 60s who had just retired, and finally made the decision to purchase the car with his dream engine," said Mazda dealer Tsunoda. "The rotary lovers are truly car fans."
For those who already own rotary powered cars such as Kiyotake Naoi, the sound and feel of the engine on his 1989 RX-7 coupe will be hard to replicate, no matter what the fuel efficiency is.
"It's like the car is a part of you," said Naoi, 38, a video game maker. "I'll probably keep this car until it breaks down so badly that I won't be able to ride it anymore."